Add a new simple utility optimization pass for serialization of SILModules

Author: swiftix

include/swift/SILOptimizer/PassManager/Passes.def

@@ -269,6 +269,8 @@ PASS(MarkUninitializedFixup, "mark-uninitialized-fixup",
      "Temporary pass for staging in mark_uninitialized changes.")
 PASS(SimplifyUnreachableContainingBlocks, "simplify-unreachable-containing-blocks",
      "Utility pass. Removes all non-term insts from blocks with unreachable terms")
+PASS(SerializeSILPass, "serialize-sil",
+     "Utility pass. Serializes the current SILModule")
 PASS(BugReducerTester, "bug-reducer-tester",
      "sil-bug-reducer Tool Testing by Asserting on a Sentinel Function")
 PASS_RANGE(AllPasses, AADumper, BugReducerTester)

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -243,10 +243,16 @@ void addSSAPasses(SILPassPipelinePlan &P, OptimizationLevelKind OpLevel) {
     P.addEarlyInliner();
     break;
   case OptimizationLevelKind::MidLevel:
-    // Does inline semantics-functions (except "availability"), but not
-    // global-init functions.
     P.addGlobalOpt();
     P.addLetPropertiesOpt();
+    // It is important to serialize before any of the @_semantics
+    // functions are inlined, because otherwise the information about
+    // uses of such functions inside the module is lost,
+    // which reduces the ability of the compiler to optimize clients
+    // importing this module.
+    P.addSerializeSILPass();
+    // Does inline semantics-functions (except "availability"), but not
+    // global-init functions.
     P.addPerfInliner();
     break;
   case OptimizationLevelKind::LowLevel:

lib/SILOptimizer/UtilityPasses/CMakeLists.txt

@@ -21,6 +21,7 @@ set(UTILITYPASSES_SOURCES
   UtilityPasses/LoopRegionPrinter.cpp
   UtilityPasses/MemBehaviorDumper.cpp
   UtilityPasses/RCIdentityDumper.cpp
+  UtilityPasses/SerializeSILPass.cpp
   UtilityPasses/SILDebugInfoGenerator.cpp
   UtilityPasses/SideEffectsDumper.cpp
   UtilityPasses/SimplifyUnreachableContainingBlocks.cpp

lib/SILOptimizer/UtilityPasses/SerializeSILPass.cpp

@@ -0,0 +1,53 @@
+//===--- SerializeSILPass.cpp ---------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "serialize-sil"
+#include "swift/Strings.h"
+#include "swift/SILOptimizer/PassManager/Passes.h"
+#include "swift/SILOptimizer/PassManager/Transforms.h"
+
+using namespace swift;
+
+/// A utility pass to serialize a SILModule at any place inside the optimization
+/// pipeline.
+class SerializeSILPass : public SILModuleTransform {
+  /// Removes [serialized] from all functions. This allows for more
+  /// optimizations and for a better dead function elimination.
+  void removeSerializedFlagFromAllFunctions(SILModule &M) {
+    for (auto &F : M) {
+      F.setSerialized(IsSerialized_t::IsNotSerialized);
+    }
+  }
+
+public:
+  SerializeSILPass() {}
+  void run() override {
+    auto &M = *getModule();
+    // Nothing to do if the module was serialized already.
+    if (M.isSerialized())
+      return;
+
+    // Mark all reachable functions as "anchors" so that they are not
+    // removed later by the dead function elimination pass. This
+    // is required, because clients may reference any of the
+    // serialized functions or anything referenced from them. Therefore,
+    // to avoid linker errors, the object file of the current module should
+    // contain all the symbols which were alive at the time of serialization.
+    DEBUG(llvm::dbgs() << "Serializing SILModule in SerializeSILPass\n");
+    getModule()->serialize();
+    removeSerializedFlagFromAllFunctions(M);
+  }
+};
+
+SILTransform *swift::createSerializeSILPass() {
+  return new SerializeSILPass();
+}

test/SILOptimizer/closure_specialize_fragile.sil

@@ -0,0 +1,60 @@
+// RUN: %target-sil-opt  %s -verify -closure-specialize -assume-parsing-unqualified-ownership-sil -o -  | %FileCheck %s
+
+// Make sure we do not specialize resilientCallee.
+
+sil_stage canonical
+
+import Builtin
+import Swift
+import SwiftShims
+
+@_semantics("optimize.sil.never") public func action()
+
+@inline(__always) public func fragileCaller()
+
+public func resilientCallee(fn: () -> ())
+
+// action()
+sil [_semantics "optimize.sil.never"] @_T026closure_specialize_fragile6actionyyF : $@convention(thin) () -> () {
+bb0:
+  %0 = tuple ()
+  return %0 : $()
+} // end sil function '_T026closure_specialize_fragile6actionyyF'
+
+// CHECK-LABEL: sil [serialized] [always_inline] @_T026closure_specialize_fragile0C6CalleryyF : $@convention(thin) () -> ()
+// CHECK: function_ref @_T026closure_specialize_fragile15resilientCalleeyyyc2fn_tF : $@convention(thin) (@owned @callee_owned () -> ()) -> ()
+// CHECK: return
+// fragileCaller()
+sil [serialized] [always_inline] @_T026closure_specialize_fragile0C6CalleryyF : $@convention(thin) () -> () {
+bb0:
+  // function_ref resilientCallee(fn:)
+  %0 = function_ref @_T026closure_specialize_fragile15resilientCalleeyyyc2fn_tF : $@convention(thin) (@owned @callee_owned () -> ()) -> ()
+  // function_ref closure #1 in fragileCaller()
+  %1 = function_ref @_T026closure_specialize_fragile0C6CalleryyFyycfU_ : $@convention(thin) () -> () 
+  %2 = thin_to_thick_function %1 : $@convention(thin) () -> () to $@callee_owned () -> () 
+  %3 = apply %0(%2) : $@convention(thin) (@owned @callee_owned () -> ()) -> ()
+  %4 = tuple ()
+  return %4 : $()
+} // end sil function '_T026closure_specialize_fragile0C6CalleryyF'
+
+// CHECK-LABEL: sil @_T026closure_specialize_fragile15resilientCalleeyyyc2fn_tF : $@convention(thin) (@owned @callee_owned () -> ()) -> ()
+
+// resilientCallee(fn:)
+sil @_T026closure_specialize_fragile15resilientCalleeyyyc2fn_tF : $@convention(thin) (@owned @callee_owned () -> ()) -> () {
+bb0(%0 : $@callee_owned () -> ()):
+  strong_retain %0 : $@callee_owned () -> ()
+  %3 = apply %0() : $@callee_owned () -> ()
+  strong_release %0 : $@callee_owned () -> ()
+  %5 = tuple ()
+  return %5 : $()
+} // end sil function '_T026closure_specialize_fragile15resilientCalleeyyyc2fn_tF'
+
+// closure #1 in fragileCaller()
+sil shared [serialized] @_T026closure_specialize_fragile0C6CalleryyFyycfU_ : $@convention(thin) () -> () {
+bb0:
+  // function_ref action()
+  %0 = function_ref @_T026closure_specialize_fragile6actionyyF : $@convention(thin) () -> () 
+  %1 = apply %0() : $@convention(thin) () -> ()
+  %2 = tuple ()
+  return %2 : $()
+} // end sil function '_T026closure_specialize_fragile0C6CalleryyFyycfU_'

test/SILOptimizer/closure_specialize_fragile.swift

@@ -17,7 +17,7 @@ _ = testit()
 // CHECK: sil hidden @{{.*}}testit
 
 // CHECK:      // MyStruct.StaticVar.getter
-// CHECK-NEXT: sil private [serialized] @_{{.*}}StaticVar
+// CHECK-NEXT: sil private @_{{.*}}StaticVar
 
 // CHECK:      // Global.getter
-// CHECK-NEXT: sil private [serialized] @_{{.*}}Global
+// CHECK-NEXT: sil private @_{{.*}}Global

test/SILOptimizer/globalopt_linkage.swift

@@ -16,7 +16,7 @@
 // initialization code could be removed.
 // Specifically, the initialization code for Prop1, Prop2 and Prop3 can be removed.
 
-// CHECK-WMO-LABEL: sil [thunk] [always_inline] @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int32, @owned Foo) -> @owned Foo
+// CHECK-WMO-LABEL: sil @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int32, @owned Foo) -> @owned Foo
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop1
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop2
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop3
@@ -26,7 +26,7 @@
 // CHECK-WMO: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop3
 // CHECK-WMO: return
 
-// CHECK-WMO-LABEL: sil [thunk] [always_inline] @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int64, @owned Foo) -> @owned Foo
+// CHECK-WMO-LABEL: sil @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int64, @owned Foo) -> @owned Foo
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop1
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop2
 // CHECK-WMO-NOT: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop3
@@ -41,14 +41,14 @@
 // from other modules. Therefore the initialization code could be removed.
 // Specifically, the initialization code for Prop2 can be removed.
 
-// CHECK-LABEL: sil [thunk] [always_inline] @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int32, @owned Foo) -> @owned Foo
+// CHECK-LABEL: sil @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int32, @owned Foo) -> @owned Foo
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop0
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop1
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop2
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop3
 // CHECK: return
 
-// CHECK-LABEL: sil [thunk] [always_inline] @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int64, @owned Foo) -> @owned Foo
+// CHECK-LABEL: sil @_T019let_properties_opts3FooC{{[_0-9a-zA-Z]*}}fc : $@convention(method) (Int64, @owned Foo) -> @owned Foo
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop0
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop1
 // CHECK: ref_element_addr %{{[0-9]+}} : $Foo, #Foo.Prop2

test/SILOptimizer/let_properties_opts.swift

@@ -53,7 +53,7 @@ public func testOutlining() {
   gizmo.doSomething(arr)
 }
 
-// CHECK-LABEL: sil shared [serializable] [noinline] @_T0So5GizmoC14stringPropertySQySSGvgToTeab_ : $@convention(thin) (@in_guaranteed Gizmo) -> @owned Optional<String>
+// CHECK-LABEL: sil shared [noinline] @_T0So5GizmoC14stringPropertySQySSGvgToTeab_ : $@convention(thin) (@in_guaranteed Gizmo) -> @owned Optional<String>
 // CHECK: bb0(%0 : $*Gizmo):
 // CHECK:   %1 = load %0 : $*Gizmo
 // CHECK:   %2 = objc_method %1 : $Gizmo, #Gizmo.stringProperty!getter.1.foreign : (Gizmo) -> () -> String!
@@ -71,7 +71,7 @@ public func testOutlining() {
 // CHECK: bb3(%13 : $Optional<String>):
 // CHECK:   return %13 : $Optional<String>
 
-// CHECK-LABEL: sil shared [serializable] [noinline] @_T0So5GizmoC14stringPropertySQySSGvgToTepb_ : $@convention(thin) (Gizmo) -> @owned Optional<String>
+// CHECK-LABEL: sil shared [noinline] @_T0So5GizmoC14stringPropertySQySSGvgToTepb_ : $@convention(thin) (Gizmo) -> @owned Optional<String>
 // CHECK: bb0(%0 : $Gizmo):
 // CHECK:  %1 = objc_method %0 : $Gizmo, #Gizmo.stringProperty!getter.1.foreign : (Gizmo) -> () -> String!
 // CHECK:  %2 = apply %1(%0) : $@convention(objc_method) (Gizmo) -> @autoreleased Optional<NSString>
@@ -88,7 +88,7 @@ public func testOutlining() {
 // CHECK:bb3(%12 : $Optional<String>):
 // CHECK:  return %12 : $Optional<String>
 
-// CHECK-LABEL: sil shared [serializable] [noinline] @_T0So5GizmoC14stringPropertySQySSGvsToTembnn_ : $@convention(thin) (@owned String, Gizmo) -> () {
+// CHECK-LABEL: sil shared [noinline] @_T0So5GizmoC14stringPropertySQySSGvsToTembnn_ : $@convention(thin) (@owned String, Gizmo) -> () {
 // CHECK: bb0(%0 : $String, %1 : $Gizmo):
 // CHECK:   %2 = objc_method %1 : $Gizmo, #Gizmo.stringProperty!setter.1.foreign : (Gizmo) -> (String!) -> ()
 // CHECK:   %3 = function_ref @_T0SS10FoundationE19_bridgeToObjectiveCSo8NSStringCyF : $@convention(method) (@guaranteed String) -> @owned NSString
@@ -99,7 +99,7 @@ public func testOutlining() {
 // CHECK:   strong_release %4 : $NSString
 // CHECK:   return %7 : $()
 
-// CHECK-LABEL: sil shared [serializable] [noinline] @_T0So5GizmoC12modifyStringSQySSGAD_Si10withNumberSQyypG0D6FoobartFToTembnnnb_ : $@convention(thin) (@owned String, Int, Optional<AnyObject>, Gizmo) -> @owned Optional<String> {
+// CHECK-LABEL: sil shared [noinline] @_T0So5GizmoC12modifyStringSQySSGAD_Si10withNumberSQyypG0D6FoobartFToTembnnnb_ : $@convention(thin) (@owned String, Int, Optional<AnyObject>, Gizmo) -> @owned Optional<String> {
 // CHECK: bb0(%0 : $String, %1 : $Int, %2 : $Optional<AnyObject>, %3 : $Gizmo):
 // CHECK:   %4 = objc_method %3 : $Gizmo, #Gizmo.modifyString!1.foreign : (Gizmo) -> (String!, Int, Any!) -> String!
 // CHECK:   %5 = function_ref @_T0SS10FoundationE19_bridgeToObjectiveCSo8NSStringCyF : $@convention(method) (@guaranteed String) -> @owned NSString
@@ -124,7 +124,7 @@ public func testOutlining() {
 // CHECK: bb3(%20 : $Optional<String>):
 // CHECK:   return %20 : $Optional<String>
 
-// CHECK-LABEL: sil shared [serializable] [noinline] @_T0So5GizmoC11doSomethingSQyypGSQySaySSGGFToTembnn_ : $@convention(thin) (@owned Array<String>, Gizmo) -> @owned Optional<AnyObject> {
+// CHECK-LABEL: sil shared [noinline] @_T0So5GizmoC11doSomethingSQyypGSQySaySSGGFToTembnn_ : $@convention(thin) (@owned Array<String>, Gizmo) -> @owned Optional<AnyObject> {
 // CHECK: bb0(%0 : $Array<String>, %1 : $Gizmo):
 // CHECK:   %2 = objc_method %1 : $Gizmo, #Gizmo.doSomething!1.foreign : (Gizmo) -> ([String]!) -> Any!
 // CHECK:   %3 = function_ref @_T0Sa10FoundationE19_bridgeToObjectiveCSo7NSArrayCyF : $@convention(method) <{{.*}}> (@guaranteed Array<{{.*}}>) -> @owned NSArray

test/SILOptimizer/outliner.swift

@@ -0,0 +1,37 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -O -module-name Swift -module-link-name swiftCore -parse-as-library -parse-stdlib -emit-module -sil-serialize-witness-tables -sil-serialize-vtables %s -o %t/Swift.swiftmodule
+// RUN: %target-sil-opt -enable-sil-verify-all %t/Swift.swiftmodule -o - | %FileCheck %s
+
+// Test that early serialization works as expected:
+// - it happens before the performance inlining and thus preserves @_semantics functions
+// - it happens after generic specialization
+
+public struct Int {
+  @_inlineable
+  public init() {}
+}
+
+public struct Array<T> {
+  @_inlineable
+  public init() {}
+
+  // Check that the generic version of a @_semantics function is preserved.
+  // CHECK: sil [serialized] [_semantics "array.get_capacity"] @_T0Sa12_getCapacitySiyF : $@convention(method) <T> (Array<T>) -> Int
+  // Check that a specialized version of a function is produced
+  // CHECK: sil shared [serializable] [_semantics "array.get_capacity"] @_T0Sa12_getCapacitySiyFSi_Tgq5 : $@convention(method) (Array<Int>) -> Int
+  @_inlineable
+  @_versioned
+  @_semantics("array.get_capacity")
+  internal func _getCapacity() -> Int {
+    return Int()
+  }
+}
+
+// Check that a call of a @_semantics function was not inlined if early-serialization is enabled.
+// CHECK: sil [serialized] @_T0s28userOfSemanticsAnnotatedFuncSiSaySiGF
+// CHECK: function_ref
+// CHECK: apply
+@_inlineable
+public func userOfSemanticsAnnotatedFunc(_ a: Array<Int>) -> Int {
+  return a._getCapacity()
+}